New Found ‘Obelisks’ Join Viruses, Viroids as Third unusual Life form

Science , World :-  In a groundbreaking revelation, researchers at Stanford University have uncovered a new and surprisingly uncomplicated form of life called 'obelisks.' Placed in the spectrum of complexity between viruses and viroids, these findings emerged from a thorough examination of genetic material extracted from bacteria residing in the human gut, using a cutting-edge method known as next-generation sequencing (NGS).

NGS is a sophisticated technique that allows scientists to simultaneously sequence genomes from various organisms in fragments. It's like reading multiple books at the same time, but in small sections. Through this advanced approach, researchers identified a new category of life, the obelisks, standing alongside viruses and viroids in the intricate web of biological simplicity.

Viruses and Viroids: The Pioneers

For nearly seven decades, viruses were considered the sole inhabitants on the border between life and non-life. They consist of a core made of nucleic acid (either DNA or RNA), surrounded by a protein coat and sometimes a lipid layer. Viruses replicate by infecting host cells and utilizing their machinery to produce more viruses.

The viroids, discovered in 1971 by Theodor Diener, added a twist to this narrative. These simple organisms responsible for potato spindle tuber disease consisted only of naked RNA without the usual lipid layer or protein coat found in viruses. Unlike viruses, viroids don't code for any proteins; they simply propagate themselves. This discovery expanded our understanding of plant pathology, challenging the exclusive status of viruses on the border of life.

Unveiling Obelisks through NGS

Enter obelisks – a new addition to the family of micro-scale life forms. By utilizing NGS, researchers developed a special software script to identify circular RNA genomes, a characteristic feature of viroid-like entities. Analyzing a staggering 5.4 million RNA sequences from human gut bacteria, they uncovered 29,959 distinct obelisks across 220,000 datasets.

Surprisingly, obelisks were not confined to the gut alone. Further exploration revealed their presence in bacteria from the human mouth and across all seven continents, underlining their widespread distribution. In contrast to viroids, obelisks possess larger RNA genomes of around a thousand base pairs, seemingly coding for two unique proteins previously unseen in other life forms.

Linking Obelisks to S. sanguini

The challenge lies in linking specific obelisks to their bacterial hosts due to the collective analysis of RNA data from gut or oral bacteria. However, researchers overcame this hurdle by individually scrutinizing RNA from lab-grown bacteria. This led to the successful identification of a particular obelisk linked to Streptococcus sanguini, a common species in the human mouth.

This discovery sparks numerous questions about obelisks, including their replication process, transmission methods, potential impact on bacteria, evolutionary history, and implications for human health and disease. Despite these uncertainties, the finding emphasizes the blurred lines between life and non-life, shedding light on the intricate complexity and diversity of microscopic life forms within the human body.

 The identification of obelisks stands as a significant milestone in our understanding of the hidden world of microorganisms. As scientists continue to unravel the mysteries surrounding these simple life forms, we find ourselves on the brink of a new frontier where the boundaries between life and non-life become increasingly blurred.